1. Field of the Invention
This invention relates generally to burners for combustible material and, more particularly, is directed a burner nozzle assembly for a gas burner.
2. Description of the Prior Art
With burner assemblies, it is desirable to provide accurate adjustment of the amount of fluid utilized in the burner assembly. To this end, it is known to adjust the oil or gas flow in an oil or gas burner by means of a nozzle having a single orifice plug which is axially movable with respect to the opening of the nozzle. Examples of such arrangements are shown and disclosed in U.S. Pat. No. 1,731,090; 1,774,953; 1,903,100; 2,003,827; 2,290,785; 3,782,884; and 4,152,843.
Arrangements of the above type have not been limited in use with oil or gas burners. For example, U.S. Pat. No. Re. 26,013 and U.S. Pat. Nos. 3,102,691; 3,111,271; and 3,684,192 disclose hose nozzles or the like which also include an orifice plug which is axially movable with respect to the opening of the nozzle for adjusting the flow of liquid therethrough. Of these patents, U.S. Pat. No. 3,684,192 discloses such a nozzle which provides constant pressure, variable flow, regardless of the pressure from the source.
However, it may be difficult to control the amount and pressure of gas in a gas burner with the above arrangements. To do so may require use of the arrangement disclosed in U.S. Pat. No. 3,684,192, which is relatively complicated and which may be impractical in a gas burner assembly.
It is also known to separate a gas stream into a plurality of streams. For example, U.S. Pat. No. 2,914,257 discloses a combination burner nozzle in which a first circumferentially arranged set of apertures is positioned in staggered relation to a second circumferentially arranged set of apertures for dividing the gas or steam from the chamber into a plurality of streams. After being divided into the plurality of streams, the gas passes outward of the apparatus through grooves in the beveled surface of the outlet section.
U.S. Pat. No. 4,285,664 to the same inventor herein discloses a burner for a plurality of fluid streams and is generally of the type to which the present invention is directed. With the burner of this latter apparatus, however, there is no adjustment of the gas pressure or velocity at the outlet side of the burner nozzle. This patent also discloses a bluff body effect which is produced by the flat downstream end of a velocity ring by which a toroidal eddy is produced.